Improvement in gold-amalgamators



H. BREVOORT. GOLD AMALGAMATOR.

No. 25,242. Patented Aug. 30, 1859.

Q. f zumf v/y M e @A/M UNITED STATES OFFICE.

PATENT HENRY BREVOORT, OF SAN FRANCISCO, CALIFORNIA.

IMPROVEMENT IN GOLD-AMALGAMATORS.

To all whom it may concern:

Be it known that I, HENRY Bnnvoonr, of the city and county of San Francisco and State of California, have invented certain new and useful Improvements in the Method and Machinery for Amalgamating the Gold that exists in Auriferous Materials; and I do hereby declare that the following is a full, clear, and exact description of my said invention, reference being had to the accompanying drawin gs, which form part of this specification, and in which- Figure 1 represents a plan of my improved amalgamat-or. Fig. 2 represents a vertical section through the pan and shoe of the same. Fig. 3 represents a horizontal section of the bottom of the amalgamator drag or shoe; and Fig. 4 represents a transverse section of the same at the line 0 (Z of Fig 1. v

Aurit'erous materials in a pulverulent state have been treated with mercury for the purpose. of amalgamatingthe gold in an arrastra or panformed vessel in which a fiat-bottomed drag is caused to revolve. Such arrastras are objectionable on aecountof the oxidation of the mercury which arises from the continued rubbing of it by the surface of the drag, hence their employment is attended with a great loss of mercury.

The object-of the first part of my invention is to obviate this defect; and it consists in constructin g the bottom or shoe of the drag in the form of a series of blocksand rubbing-surfaces or channels reciprocally arranged in such manner that the mercury is alternately spread'out by the blocks into thin layers and permitted to collect again in mass before a second spreading.

The object of the second part of my invention is to gather together the mercury in mass after each passage of thedrag and to impede it from remaining in the form of fine particles disseminated in the material under treatment; and it consists in combining with a revolving shoe a circular pan, whose bottom has the sectional form of two inclined planes terminating at a place intermediate between the center and the periphery in a circular trough, in which the mercury is gathered in mass after each passage of the shoe to be respread into thin layers at the succeeding passage thereof.

The object of the third part of my invention is to enable me to apply a galvanic current to the mercury during the amalgamation, to facilitate this operation and it consists in combinin g a galvanic battery with the revolving shoe of an arastra in such manner that every part of the mercury is successively subjected to the influence 0f the galvanic current.

The object of the last part of my invention is to facilitatethe amalgamation of the gold of auriferous materials, particularly those containin g undecom posed metallic sulphurets and. arsenurets; and it consists in treating the ma.- terial while in the arrastra with asolution of the nitrate of mercury while it is subjected to the action of agalvanie current, whereby the amalgamation is greatly facilitated, arising, it is believed, from the continued decomposition of the nitrate and the deposition of the mercury upon the gold and the continued reformation of nitrate from the free mercury in the pan by the nitric acid set free by the decomposition.

The am algamator represented in the annexed drawings is designed to operate with all my improvements.

The pan A of the amalgamator is circular and is formed of-cast iron, its dimensions bein g thirty inches in diameter and teninches in depth, this being a convenient size for practical operation. At one side of this pan-there are three openings, 1 2 3, for the discharge of the spentmaterial. The bottom of the pan inclines from its center toward the periphery, and from its periphery toward its center, so as to form two circular inclined planes which meet in a circular trough, B, situated about midway between the center of the pan and the I periphery thereof.' The pan has an orifice, 4, leading from the trough B for the discharge of the mercury therein. It has also a hub, C, at its center in which the lower end of an upright shaft, D, is stepped, the upper end thereofbeing supported by a suitable frame. This shaft is fitted with a driving-arm, E, from which two drivers, to a, depend, that give motion to the drag F. The drag has the form of a pan whose sides are sufficientl y high to prevent the auriferous' material under treatment from lodging upon its upper surface. It has two sockets, f f, in which the drivers at a fit loosely, so that the drag can rise and fall; and its lower face is shod with a-shoe, G, which is caused to move with the drag by means of projectionsee,which enter in the sockets of the latter. The lower face of this shoe is formed into a series of blocks of rubbing-surfaces, 0, and of channels 1?, the two alternating, as shown at Fig. 3, and the front extremities of the blocks are inclined, as shown at Fig. 4, so as to enable them to conduct the material under treatment beneath the rubbingsurfaces. The drag carries the jars c c c of the galvanic battery, whose conducting-wires are carried down behind the drag and terminate in poles in'the circular trough. Motion is im parted to the drag by means of the central shaft, D, which should be caused to revolve at aspeed of about fifteen revolutions per minute. 7

When the amalgamator thus described is to be used the discharge-orifices are closedaud the circular trough is charged with about twelve pounds of mercury. From twenty-five to thirty pounds of finely-pulverized auriferous material are then placed in the pan,together with a sufficient amount of water to makeit into a pasty mass, which is moistened with about a pint of weak solution of the nitrate of mercury. The drag is then put in motion and is kept in motion'nntil complete amalgamation takes place, which generally requires from thirty to sixty minutes. During the operation the material is alternately subjected to the action of the rubbing-surfaces and is permitted to collect in the channels between them, and the mercury is alternately spread into thin layers and is permitted to recollect in the channels and flow back into the trough, where it collects 'in mass. During the amalgamation the mass is traversed by the galvanic current, and as the conducting -wires-'are carried round by the revolving shoe, every-part of the material in succession is subjected to" its action. When amalgamation has taken place water is conducted into the pan and the dischargeorifices at the side are opened in succession. By the action of this water the lighter particles of the spent material are washed 0E through the upper two orifices. Subsequently the motion of the drag is arrested and the lowest orifice, 3, in the side of the pan is opened,

when a final discharge of the material takes place nearly down to the surface of the mercury. The orifices are then closed, the machine is charged with a fresh quantityof auriferous material and nitrate, and the operation is conducted as before. When by a succession of operations the mercury has become sufii cientlycharged with gold, it is permitted to flow out of the orifice 4 in the trough and is replaced by fresh mercury.

Having thus described my invention, 1 wish it to be understood that I do not claim the amalgamation of auriferous material in a pan drawings, so as to collect the mercury in mass.

3. Combining an amalgamating-pan and revolving drag with agalvanic battery arranged in such manner that its poles are extended into the mass of material in the pan and that the parts of the material are subjected in succession to the action of the galvanic current.

4. The employment of a solution of the nitrate of mercury in connection with a galvanic battery and a friction-amalgamat-or containin g mercury, substantially as herein set forth.

In testimony whereof I have hereunto subscribed my name.

HENRY BREVOORT.

Witnesses H. B. MoNEIL, 1. 0mm. 

